Recent Life Events Preceding Suicide Attempts in a Personality Disorder Sample: Findings From the Collaborative Longitudinal Personality Disorders Study.

Few studies have examined the relationship between life events, suicide attempts, and personality disorders (PDs), in spite of the strong associations between PDs and suicidal behavior, and the poor coping strategies often exhibited by these individuals. The authors examined whether participants with PDs who attempted suicide during the first 3 years of a prospective, longitudinal study were more likely to experience specific life events in the month during and preceding the suicide attempt. Of 489 participants with PDs, 61 attempted suicide during the 3-year, follow-up interval. Results indicated that negative life events, particularly those pertaining to love-marriage or crime-legal matters, were significant predictors of suicide attempts, even after controlling for baseline diagnoses of borderline PD, major depressive disorders, substance use disorders, and a history of childhood sexual abuse. Therefore, certain types of negative life events are unique risk factors for imminent suicide attempts among individuals with PDs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Combined numerical and linguistic knowledge representation and its application to medical diagnosis

In this paper, we propose a novel hybrid intelligent system (HIS) which provides a unified integration of numerical and linguistic knowledge representations. The proposed HIS is a hierarchical integration of an incremental learning fuzzy neural network (ILFN) and a linguistic model, i.e., fuzzy expert system (FES), optimized via the genetic algorithm (GA). The ILFN is a self-organizing network. The linguistic model is constructed based on knowledge embedded in the trained ILFN or provided by the domain expert. The knowledge captured from the low-level ILFN can be mapped to the higher level linguistic model and vice versa. The GA is applied to optimize the linguistic model to maintain high accuracy, comprehensibility, completeness, compactness, and consistency. The resulted HIS is capable of dealing with low-level numerical computation and higher level linguistic computation. After the system is completely constructed, it can incrementally learn new information in both numerical and linguistic forms. To evaluate the system's performance, the well-known benchmark Wisconsin breast cancer data set was studied for an application to medical diagnosis. The simulation results have shown that the proposed HIS performs better than the individual standalone systems. The comparison results show that the linguistic rules extracted are competitive with or even superior to some well-known methods. Our interest is not only on improving the accuracy of the system, but also enhancing the comprehensibility of the resulted knowledge representation.     

Priority conflict-free Petri nets

A number of problems concerning priority conflict-free Petri nets are investigated in this paper. We show the reachability problem for such Petri nets to be NP-complete. (Using a similar technique, the NP-completeness result applies to the class of priority BPP-nets as well.) As for the boundedness problem, an NP-completeness result is demonstrated for priority conflict-free Petri nets with two types of prioritized transitions. (In contrast, the problem is known to be P-complete for conflict-free Petri nets without priorities.) We also investigate the home state problem, i.e., the problem of determining whether home states exist in a given a Petri net, for conflict-free Petri nets with and without priorities. As it turns out, home states always exist for bounded conflict-free Petri nets without priorities. If an additional liveness constraint is imposed, such Petri nets are guaranteed to be ‘reversible’ (i.e., their initial states are home states). For priority conflict-free Petri nets, being bounded and live is sufficient for the existence of home states. However, if the liveness assumption is dropped, the existence of home states is no longer guaranteed. Received: 1 April 1997 / 8 December 1997     

Systematic reliability analysis of a class of application-specific embedded software framework

Dramatic advances in computer and communication technologies have made it economically feasible to extend the use of embedded computer systems to more and more critical applications. At the same time, these embedded computer systems are becoming more complex and distributed. As the bulk of the complex application-specific logic of these systems is realized by software, the need for certifying software systems has grown substantially. While relatively mature techniques exist for certifying hardware systems, methods of rigorously certifying software systems are still being actively researched. Possible certification methods for embedded software systems range from formal verification to statistical testing. These methods have different strengths and weaknesses and can be used to complement each other. One potentially useful approach is to decompose the specification into distinct aspects that can be independently certified using the method that is most effective for it. Even though substantial-research has been carried out to reduce the complexity of the software system through decomposition, one major hurdle is the need to certify the overall system on the basis of the aspect properties. One way to address this issue is to focus on architectures in which the aspects are relatively independent of each other. However, complex embedded systems are typically comprised of multiple architectures. We present an alternative approach based on the use of application-oriented-frameworks for implementing embedded systems. We show that it is possible to design such frameworks for embedded applications and derive expressions for determining the system reliability from the reliabilities of the framework and the aspects. The method is illustrated using a distributed multimedia collaboration system.     

Associations in the Course of Personality Disorders and Axis I Disorders Over Time.

In this study, the authors examined time-varying associations between schizotypal (STPD), borderline (BPD), avoidant (AVPD), or obsessive-compulsive (OCPD) personality disorders and co-occurring Axis I disorders in 544 adult participants from the Collaborative Longitudinal Personality Disorders Study. The authors tested predictions of specific longitudinal associations derived from a model of crosscutting psychobiological dimensions (L. J. Siever & K. L. Davis, 1991) with participants with the relevant Axis I disorders. The authors assessed participants at baseline and at 6-, 12-, and 24-month follow-up evaluations. BPD showed significant longitudinal associations with major depressive disorder and posttraumatic stress disorder. AVPD was significantly associated with anxiety disorders (specifically social phobia and obsessive-compulsive disorder). Two of the four personality disorders under examination (STPD and OCPD) showed little or no association with Axis I disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two-Year Stability and Change of Schizotypal, Borderline, Avoidant, and Obsessive-Compulsive Personality Disorders.

The authors examined the stability of schizotypal (STPD), borderline (BPD), avoidant (AVPD) and obsessive-compulsive (OCPD) personality disorders (PDs) over 2 years of prospective multiwave follow-up. Six hundred thirty-three participants recruited at 4 collaborating sites who met criteria for 1 or more of the 4 PDs or for major depressive disorder (MOD) without PD were assessed with semistructured interviews at baseline, 6, 12, and 24 months. Lifetable survival analyses revealed that the PD groups had slower time to remission than the MDD group. Categorically, PD remission rates range from 50% (AVPD) to 61% (STPD) for dropping below diagnostic threshold on a blind 24-month reassessment but range from 23% (STPD) to 38% (OCPD) for a more stringent definition of improvement. Dimensionally, these findings suggest that PDs may be characterized by maladaptive trait constellations that are stable in their structure (individual differences) but can change in severity or expression over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding Computational Analyses

Johnson-Cook strength material model is frequently used in finite-element analyses of various manufacturing processes involving plastic deformation of metallic materials. The main attraction to this model arises from its mathematical simplicity and its ability to capture the first-order metal-working effects (e.g., those associated with the influence of plastic deformation, rate of deformation, and the attendant temperature). However, this model displays serious shortcomings when used in the engineering analyses of various hot-working processes (i.e., those utilizing temperatures higher than the material recrystallization temperature). These shortcomings are related to the fact that microstructural changes involving: (i) irreversible decrease in the dislocation density due to the operation of annealing/recrystallization processes; (ii) increase in grain-size due to high-temperature exposure; and (iii) dynamic-recrystallization-induced grain refinement are not accounted for by the model. In this study, an attempt is made to combine the basic physical-metallurgy principles with the associated kinetics relations to properly modify the Johnson-Cook material model, so that the model can be used in the analyses of metal hot-working and joining processes. The model is next used to help establish relationships between process parameters, material microstructure and properties in friction stir welding welds of AA5083 (a non-age-hardenable, solid-solution strengthened, strain-hardened/stabilized Al-Mg-Mn alloy).     

Control of Stress Concentration in Surface‐Mounted Multilayer Ceramic Capacitor Subjected to Bending

Failure of surface‐mounted multilayer ceramic capacitor (MLCC) results mainly from bending of the printed circuit board during handling and applications. Cracking of MLCC normally initiates at the junction of the bottom end of termination and the dielectric ceramics and it would cut through dielectric ceramics and electrodes to result in the capacitance loss and failure of MLCC. The purpose of this study was to mitigate the stress concentration and to shift the stress concentration location toward the side end of MLCC to minimize the number of electrodes cut by cracking. To achieve this, effects of the stiffness and the thickness of the solder and the size of MLCC on the location of crack initiation and the fracture load were examined. Nanoindentation was performed to obtain the mechanical properties of the constituents of the system. Finite element analyses were conducted to simulate the stress field in the surface‐mounted MLCC subjected to bending and the results were compared to the observed crack initiation locations and the fracture load. The outcome would provide guidelines in mounting and designing of MLCCs to enhance its reliability and lifetime.